We found this circuit in a 1956 Sylvania publication. It serves to monitor telegraph transmissions being placed next to the transmitter. The circuit is indicated for the range of 80 and 160 meters.
This circuit was found in an American documentation from the 80's. The components are from that...
The circuit shown is from the Texas Instruments optoelectronics manual. It is intended for audio...
This circuit drive an LED with constant current determined by the values of the resistors of 10...